斜带石斑鱼卵巢芳香化酶基因和启动子克隆与分析

ytochrome P450 aromatase (P450arom, CYP19) is a member of the cytochrome P450 superfamily. CYP19 is the key enzyme catalyzing the conversion of androgens into estrogens. Previous studies showed that there exist two types of cyp19 genes, cyp19a1a and cyp19a1b respectively, in fish，and cyp19a1a was mainly expressed in the ovary and involved in the gonadal differentiation. In the present paper, the 5'-flanking region and full length of the cyp19a1a gene in the orange-spotted grouper were successfully cloned by GenomeWalker PCR and genome PCR. The full length of cyp19a1a gene was about 3.1 kb with conserved intron-exon structures, which contains 9 exons and 8 introns, and the boundary of the intron and exon from 5'to 3'end follows the GT/AG rule. The transcription element search system (TESS) was employed to analyze the 5'-flanking region of about 2.6 kb in cyp19a1a gene. In the proximal promoter region, a TATA box was identified at nucleotide (nt) -28 upstream of the putative start site, a FOXO binding site at -100 nt，a SOX bingding site at-101 nt，two FTZ-F1 binding sites at -117 nt and -145 nt, a CREB binding site at-290 nt. Presumably, FTZ-F1 is important for steroidogenesis, and CREB may mediate the stimulatory effects of gonadotropins on cyp19a1a gene in the orange-spotted grouper. The regulation of cyp19a1a promoter activity by these transcription factors was currently under way in our laboratory.